Intelligent building, smart home, and home networking are hot topics in building industry. These systems rely on a physical layer to transmit signal. Wire and wireless physical layers are commonly used. However, both layers have their limitations and associate problems especially in old buildings.
Wireless network is free in cabling, but interference and security are the big concern. Radio spectrum is a national asset in most of the country. In order to prevent interference, most of the countries legislate a series of ordinance and regulation to govern the use of atmosphere in signal transmission. Many wireless systems are using the same unlicensed band to transmit signals. Interference is unavoidable and data security is also a big concern in wireless systems. Eavesdropping is very easy in wireless networks. The attacker can easily eavesdrop on a signal outside a guarded building and decrypt the data out.
Wired network provides higher security and reliable in signal transmission but inflexibility in system reconfiguration and higher cost on cabling and associated builder work. In more than 20 year old public rental housing, there is usually no spare cable containment for future cabling. The cost for one data outlet in new building is about HK$278. For example, a new residential building with 480 flats, the cost on ancillary systems is around HK$2,015,280. In an existing old building, the cost on adding a new network is even several times higher than new building because of associated builder work such as concrete chasing.
In view of the limitations of the traditional data transmission media, an alternative way to transmit data within a building with lower cost, less nuisance to occupants in old buildings and higher data security is needed.
It is an object of the present system to overcome the disadvantages and problems in the prior art.